.\" zip_fopen.mdoc -- open file in zip archive for reading
.\" Copyright (C) 2003-2017 Dieter Baron and Thomas Klausner
.\"
.\" This file is part of libzip, a library to manipulate ZIP archives.
.\" The authors can be contacted at <libzip@nih.at>
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.Dd December 18, 2017
.Dt ZIP_FOPEN 3
.Os
.Sh NAME
.Nm zip_fopen ,
.Nm zip_fopen_index
.Nd open file in zip archive for reading
.Sh LIBRARY
libzip (-lzip)
.Sh SYNOPSIS
.In zip.h
.Ft zip_file_t *
.Fn zip_fopen "zip_t *archive" "const char *fname" "zip_flags_t flags"
.Ft zip_file_t *
.Fn zip_fopen_index "zip_t *archive" "zip_uint64_t index" "zip_flags_t flags"
.Sh DESCRIPTION
The
.Fn zip_fopen
function opens the file name
.Ar fname
in
.Ar archive .
The
.Ar flags
argument specifies how the name lookup should be done, according to
the values are described in
.Xr zip_name_locate 3 .
Also, the following values may be
.Em or Ns No 'ed
to it.
.Bl -tag -offset indent -width ZIP_FL_COMPRESSED
.It Dv ZIP_FL_COMPRESSED
Read the compressed data.
Otherwise the data is uncompressed by
.Fn zip_fread .
.It Dv ZIP_FL_UNCHANGED
Read the original data from the zip archive, ignoring any changes made
to the file; this is not supported by all data sources.
.El
.Pp
The
.Fn zip_fopen_index
function opens the file at position
.Ar index .
.Pp
If encrypted data is encountered, the functions call
.Xr zip_fopen_encrypted 3
or
.Xr zip_fopen_index_encrypted 3
respectively, using the default password set with
.Xr zip_set_default_password 3 .
.Sh RETURN VALUES
Upon successful completion, a
.Ft struct zip_file
pointer is returned.
Otherwise,
.Dv NULL
is returned and the error code in
.Ar archive
is set to indicate the error.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er ZIP_ER_CHANGED
The file data has been changed and the data source does
not support rereading data.
.It Bq Er ZIP_ER_COMPNOTSUPP
The compression method used is not supported.
.It Bq Er ZIP_ER_ENCRNOTSUPP
The encryption method used is not supported.
.It Bq Er ZIP_ER_MEMORY
Required memory could not be allocated.
.It Bq Er ZIP_ER_NOPASSWD
The file is encrypted, but no password has been provided.
.It Bq Er ZIP_ER_READ
A file read error occurred.
.It Bq Er ZIP_ER_SEEK
A file seek error occurred.
.It Bq Er ZIP_ER_WRONGPASSWD
The provided password does not match the password used for encryption.
Note that some incorrect passwords are not detected by the check done by
.Fn zip_fopen .
.It Bq Er ZIP_ER_ZLIB
Initializing the zlib stream failed.
.El
.Pp
The function
.Fn zip_fopen
may also fail and set
.Va zip_err
for any of the errors specified for the routine
.Xr zip_name_locate 3 .
.Pp
The function
.Fn zip_fopen_index
may also fail with
.Er ZIP_ER_INVAL
if
.Ar index
is invalid.
.Sh SEE ALSO
.Xr libzip 3 ,
.Xr zip_fclose 3 ,
.Xr zip_fread 3 ,
.Xr zip_fseek 3 ,
.Xr zip_get_num_entries 3 ,
.Xr zip_name_locate 3 ,
.Xr zip_set_default_password 3
.Sh HISTORY
.Fn zip_fopen
and
.Fn zip_fopen_index
were added in libzip 1.0.
.Sh AUTHORS
.An -nosplit
.An Dieter Baron Aq Mt dillo@nih.at
and
.An Thomas Klausner Aq Mt tk@giga.or.at
